1. Field of the Invention
The present invention relates to a display device. More particularly, the invention relates to a liquid crystal display device in whose manufacturing process the destruction of wiring and other parts by static electricity is effectively prevented.
2. Description of the Related Art
In the liquid crystal display device, a TFT substrate having pixel electrodes and thin film transistors (TFTs) formed in a matrix thereon is opposed to a counter substrate having color filters or overcoat films formed at the locations corresponding to the pixel electrodes of the TFT substrate, the TFT substrate and the counter substrate sandwiching a liquid crystal therebetween. The light transmission rate of liquid crystal molecules is controlled per pixel to form images.
Because it is not efficient to manufacture individual liquid crystal display panels making up the liquid crystal display device, numerous liquid crystal cells are formed on a mother substrate that is later divided into individual liquid crystal cells. In particular, the TFT substrate has numerous TFTs, video signal lines, and scanning signal lines formed with a short spacing therebetween. Static electricity, if incurred during the manufacturing process, can lead to dielectric breakdown between wires or breakdown of TFTs. To prevent such eventualities, the signal lines are connected to a common line so that static electricity will not occur between wires during the manufacturing process. On the mother substrate, the common line is connected to ground wires formed between the individual liquid crystal display panels.
JP-1999-84353-A describes a structure in which numerous liquid crystal display panels are formed on the mother substrate, the liquid crystal display panels being subjected to lighting inspection. The signal lines of the individual liquid crystal display panels are made common to each column for a single inspection. In this structure, the liquid crystal display panels arrayed in each row on the mother substrate are subjected to a single lighting inspection.